Description Of Business And Segment Reporting (Summary Of Results Of Operations For Principal Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 21,307	$ 49,228
Segment operating income (loss)	(13,977)	(7,039)
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	21,307	49,228
Segment operating income (loss)	(9,643)	(2,467)
Intersegment Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	(131)	(1,684)
Cinema Exhibition [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	18,115	46,310
Segment operating income (loss)	(8,275)	(2,654)
Real Estate [Member] | Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	3,323	4,602
Segment operating income (loss)	$ (1,368)	$ 187